The primary objective of the proposed research is to provide additional information concerning the normal pre- and postnatal development of the human visual system. Using brain material obtained during normal autopsy procedures and brain material made available through an existing slide collection, we plan to study the prenatal development of the lateral geniculate nucleus and both the pre- and postnatal development of ocular dominance columns in primary visual cortex. Once these normal sequences of development have been defined for the human visual system, they can be compared to similar sequences of development in a variety of sub-human animals. Such comparisons may make it possible to relate the point in development at which visual deprivation effects normal development in an animal like the monkey to a similar point in the normal development of the human visual system. The information gained from these studies should help to define the 'critical-period' in the development of the human visual system. A secondary objective of the proposed research is to study the morphology of human geniculate and superior colliculus cells in Golgi impregnated material.